This application is a continuation-in-part of application Ser. No. 07/152 388 filed Feb. 4, 1988, now abandoned.
This invention relates to a tubular structure for use in manufacturing for instance, fishing rods or golf shafts.
In one example of a tubular structure for manufacturing fishing rods or the like, as disclosed by Japanese Patent Application (OPI) No. 41532/1986 (the term "OPI" as used herein means an "unexamined published application"), a tube is formed by winding a prepreg sheet in such a manner as to form inner and outer prepreg sheet layers, and a single fiber of amorphous alloy is spirally or crosswise wound in such a manner as to be interposed between the inner and outer prepreg sheet layers. In another example, as disclosed by Japanese Patent Application (OPI) No. 189369/1982 tubular reinforced resin layer of high strength fibers such as carbon fibers and synthetic resin is combined with a tubular alloy layer made up of an amorphous alloy thin plate.
In the first example described above, the amorphous single fiber employed is linear, and is therefore brought into point contact with the prepreg sheet. Accordingly, the load applied thereto is concentrated; that is, winding tension in the amorphous single fiber is low.
When a fishing rod is bent, it becomes elliptic in transverse cross-section. In this case, the linear amorphous single fiber, being in point contact with the prepreg sheet, penetrates the latter in the direction of the major diameter, thus reducing the strength of the fiber wound portion of the fishing rod. Accordingly, in the fiber wound portion of the fishing rod, it is not satisfactory to wind the fiber on the prepreg sheet under high tension. As a result, the adhesion of the fiber thus wound to the prepreg sheet is low, and accordingly the inner and outer layers are subject to peeling off from each other.
In the second example of the conventional tubular structure, the amorphous alloy thin plate is spirally wound on the reinforcing resin layer to form the alloy layer. Therefore, the strength (top strength, middle strength and base strength) of the fishing rod is limited. In the case where the alloy layer is formed between the inner and outer layers, these layers are subject to peeling off from each other because they are separated from each other by the alloy layers.